MRO Magazine

How intelligent and regular machine safety audits can protect a workforce in the manufacturing industry

Safety comes at a cost, but a cost which will never be greater than the danger presented to an unprotected workforce.

November 29, 2022 | By Tim Knowles

Photo: winnievinzence / Adobe Stock.

Photo: winnievinzence / Adobe Stock.

No matter where you are in the world or what kind of facility you run, workplace safety should be at the top of your list of concerns. It represents a serious issue that needs to be addressed at every level, to keep your equipment and workers safe. In, 2020, Canadian workers compensation boards reported that 924 workers died due to work- related causes. In Nova Scotia alone, manufacturing represents nearly 11 per cent of all serious injuries in the province. The Workers’ Compensation Board of Nova Scotia states there were 516 serious injuries in the manufacturing sector in Nova Scotia in 2020.

The risk is real, and with that said, employers must be diligent to ensure their employees have the required information, training, and supervision to perform their jobs safely. They also need to ensure that machinery and equipment is kept functional and safe. All employees in the plant setting have a right to be informed of any known or foreseeable hazards in the facility and to be provided with the information, instructions, training, and supervision necessary to operate machinery and tools, all to protect their health and safety.

The easiest choice for any plant manager is to invest in the safety and wellbeing of their staff and operating equipment.

Determining risks and hazards in the workplace


There are countless features of a given manufacturing plant which could pose a risk to workers. The plate of a massive machine press being lowered onto raw materials, the sharp edge on a workstation or machine tool, or even something like excessive noise levels damaging employee hearing. It’s obvious that government safety regulations must always be followed, but plant managers must be proactive in determining the risk of a given hazard by assessing its severity, the potential for exposure, the frequency of exposure, and the duration of exposure. A company can effectively assess a risk once they have identified a potential hazard. Is the hazard near workers, are workers constantly exposed to the hazard, and what is the severity or potential injury that the hazard poses?

One of the most common methods employed in manufacturing safety is the installation of machine guarding. Put simply, machine guarding takes the form of physical barriers installed around a machine which prevents access to the hazards within. This is especially common within industrial machinery, and when designed correctly protects users from any debris which may be ejected from a given machine during operation. For example, this would protect workers in a brewery if a glass bottle exploded in the filling machine. Physical guarding is also an effective method for preventing contact with moving parts, pinch hazards, high temperature components and other hazards.

Although machine guarding is an incredibly common safety mechanism, not every machine needs machine guarding installed. The need for guarding is determined using a risk assessment, a prescribed process for ensuring that all the hazards of a machine are captured and addressed. This process can be repeated to determine the need for improved machine guarding, or a simplified process known as a hazards assessment can be performed. Both will inform plant managers of the next steps in increasing workplace safety.

Following up on risk and hazards assessments: mitigation and management

Sometimes the simplest answer is best: eliminate the presence of hazards in the workplace. But this is, of course, easier said than done. Completely eliminating the presence of hazards can be unrealistic or straight up impossible. It can be challenging to completely eliminate risks and hazards, so the focus should be on reducing the risks and hazards of a workplace. The hierarchy of risk reduction is the same regardless of injury, and is composed of the following:

  • Inherently safe design
  • Engineer out the part of the manufacturing process which is causing the hazard. For example, if operators may be exposed to hazards while loading raw materials into a machine, incorporate an automatic loading system which eliminates the potentially hazardous task.
  • Safeguarding and complimentary protective measures
  • Integrate machine guarding and other protective devices to eliminate access to the hazard. For example, if operators may be exposed to a hazard while loading raw materials into a machine, install a light curtain to stop the machine when an operator is loading the raw materials.
  • Information for use
  • Comprised of signage, training, and PPE. For example, if operators may be exposed to a hazard while loading raw materials into a machine, add a sign indicating the presence of the hazard which instructs operators on how to properly load raw materials.

It can be incredibly beneficial to approach safety with a future-oriented mind-set. If you’re already in the process of managing risks and hazards within a machine, take the time to investigate other avenues of improvement which could benefit your workforce. If a machine needs hard-wired controls installed, why not install a safety PLC, and thereby upgrade the controls system at the same time? Currently, communication protocols that can work from an ethernet network are incredibly popular. They enable full safety-rated communications without the need for additional dedicated architecture. Auxiliary upgrades such as these ensure the safety and robustness of the system into the future.

Intelligent and regular safety audits keep your workers safe, simple as that

The way workers interact with machines, and the functionality of the machines are continuously changing, so it’s important for plant managers to be ever vigilant in their approach to safety. For this reason, we recommend that safety audits be performed internally on an ongoing basis. Audits will reveal deficiencies in existing safety protocols which can then be addressed before tragedy strikes. At every manufacturing location, it is essential to set a schedule for inspecting each machine on a regular basis to ensure its safe for various teams to work with. Safety is also not static, and safety devices and procedures are constantly being improved and refined. It is important to keep abreast of developments to see if new devices, procedures, or technologies could improve the safety of existing systems. Internal audits can be tricky since they will lack fresh perspective of systems and procedures. Sometimes bringing in personnel unfamiliar with a machine to assist in a risk assessment or hazards analysis can help capture safety risks that those familiar with a machine might gloss over or take for granted.

Ideally, regular internal audits will reveal the need for external, professional safety audits to identify and address the full extent of existing risks and hazards. When a company internally determines that a machine could present a hazard to operators, or others, that is when an external expert should be introduced to the issue, and the process of remediation should begin.

The safety audit process explained

When an internal audit identifies a machine as hazardous, third-party industrial automation companies become involved at the behest of the plant manager. Usually, the first thing these companies do is interview people who regularly use the equipment to identify the issues that they feel need to be addressed. The workers who use the machine frequently are most likely to be familiar with potential issues.

After that, machine guarding receives a thorough examination as this is where most issues originate. Checking the electrical and pneumatic controls is also essential, as they are often out of date in terms of current safety standards. The most common hazards are ones that have been present for a long time. Eventually, things that have ‘always been done that way’ become ignored. It is important to stay vigilant and avoid this pitfall in the process of making workplaces safer.

Safety audits can also be performed before a machine has been purchased, in the case that a manufacturer wants to verify that the machine builder is meeting all the customer’s needs and safety standards.

How SIS levels are assigned and used during safety audits

A common aspect of safety audits is the Safety Instrumentation System, which ensures when a machine operator may encounter hazardous energies in a machine, those energies are dissipated and do not return until the operator has left the area. In Canada, the different SIS levels are referred to as performance levels and range from A (least protective) to E (most protective). Most companies aim for PLD, or performance level D. Every industry uses the same levels, but different industries trend towards the upper or lower end of the spectrum depending on the amount of capital they dedicate to safety.

Safer facilities are generally more expensive facilities. However, the safety of your workforce is priceless, and maintaining a safe manufacturing environment is much cheaper than dealing with the ministry of labour shutting down an entire facility due to a safety incident. The smart decision is to make safety a real priority. Set aside a budget each year for the improvement and maintenance of safety protocols at your facility while ensuring that employee feedback is not only listened to, but also acted upon.

For a risk assessment to be successful, it must encompass all aspects of a business’ operation. Therefore, it is essential to include representatives from operations, maintenance, sanitation, management, and any relevant groups in safety discussions. Each group must understand the risks and hazards which might be present within the part of the machine they most often work with.

Ultimately, safer machines enable easier resource distribution since they require less training on the part of a prospective operator. If safety systems across an entire facility follow the same design philosophy, it also cuts down on training time.

Safety technologies and procedures into the future

The manufacturing sector at large saw a large shift towards IoT solutions just before the beginning of the pandemic. Many refer to this shift as Industry 4.0. For now, this paradigm shift is limited to larger companies with larger safety budgets, but, over time, technological advances will trickle down into more affordable devices and systems. For the safety sector, this means better visibility into the internal logic of controllers and devices, and thus greater control over their functions. For example, before a scanner might only tell you whether something was inside its sensor’s ranger, now it will identify exactly where the object is. This is especially beneficial in robotic and self-guided vehicular applications.

Manufacturing safety in the future will likely comprise of systems which enable operators to perform tasks within one section of a machine, while other sections continue to carry out their designated functions. These advancements are already in their early stages but will only become more common as currently expensive devices such as servo motors and robots become more accessible.

Safety can never be neglected

Safety comes at a cost, but a cost which will never be greater than the danger presented to an unprotected workforce. Although ensuring the safety of a workplace and its equipment will demand a greater investment of time and money, it is always the right choice. Performing regular internal safety audits will pay off in the long run, ensuring your facility, equipment, and most importantly, your workers are kept safe and able to operate.

Tim Knowles is P. Eng., FSEng (TÜV Rhineland), is a Senior Safety Automation Specialist with Actemium Toronto


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